Rear-viewable reflective display

Abstract

A novel reflective display system is described. The display system is viewable through the display backplane instead of the counterelectrode. Making the display viewable through the backplane allows use of a conducting elastomer as a counterelectrode which facilitates fabrication of a flexible display. The rear-viewable display also facilitates attachment of color filters directly to the backplane simplifying filter pixel alignment issues.

1. A display including:
 an electronic backplane including a substantially transparent electrode, the electronic backplane includes large regions that are substantially transparent; 
 an elastomeric counter electrode layer made of an electrically conductive material; and, 
 a display media including a display material that changes reflective states in response to an applied electric field, the display material positioned between the substantially transparent electrode in the backplane and the counter electrode, the display designed such that light is reflected from the display media through the electronic backplane to an observer. 
 
   
   
     2. The display of  claim 1  wherein the counter electrode is opaque. 
   
   
     3. The display of  claim 1  wherein the counter electrode is substantially transparent. 
   
   
     4. The display of  claim 1  wherein the display material is an electrophoretic ink. 
   
   
     5. The display of  claim 4  wherein flexibility of the counter electrode and transparent electronic backplane enable flexing of the display into both concave and convex shapes. 
   
   
     6. The display of  claim 1  wherein the display material in the display media is encapsulated. 
   
   
     7. The display of  claim 1  wherein the display material relies on electro osmosis processes. 
   
   
     8. The display of  claim 1  wherein chambers are directly formed onto the backplane and filled with the electrophoretic ink. 
   
   
     9. The display of  claim 1  wherein the backplane includes an array of pixel switches to enable active matrix addressing of pixels in the display. 
   
   
     10. The display of  claim 1  wherein the counter electrode is at least semi-transparent. 
   
   
     11. The display of  claim 1  wherein the backplane includes an array of stripe electrodes to enable passive matrix addressing of pixels in the display. 
   
   
     12. The display of  claim 1  wherein the ratio of transparent areas in the backplane to opaque areas in the backplane exceeds 70%. 
   
   
     13. The display of  claim 1  wherein electronics are formed on a flexible transparent glass to form the backplane. 
   
   
     14. The display of  claim 1  wherein electronics are formed on a polyester foil to form the backplane. 
   
   
     15. The display of  claim 1  further comprising:
 a plurality of color filters, each color filter deposited over a corresponding pixel in the backplane. 
 
   
   
     16. The display of  claim 1  wherein the Young's modulus of the elastomer forming the counter electrode is between 0.01 and 0.1 Giga-Pascals. 
   
   
     17. A method of viewing a display image comprising of:
 applying a voltage potential to electronic elements such that an electric field is created between electrodes in a backplane and an elastomeric counter electrode, the electric field to cause electrophoretic ink in the display to form a desired pattern; 
 transmitting light through the backplane to the electrophoretic ink; 
 reflecting light from the electrophoretic ink back through the backplane to an observer. 
 
   
   
     18. The method of  claim 17  wherein a second voltage potential is applied to an opaque conducting elastomer that forms the counter electrode to the electrodes in the backplane. 
   
   
     19. The method of  claim 17  wherein the electronic elements are pixels in an active matrix backplane. 
   
   
     20. The method of  claim 17  wherein the electronic elements are segmented electrodes in a direct address display.